Nu-amino-nitrogen containing heterocyclic compounds



iinited States Patent G N-AMINO-NITROGEN CONTAINING HETERO- CYCLIC COMPOUNDS John H. Biel, Milwaukee, Wis, assignor, by mesne asslgnments, to Lakeside Laboratories, Inc., Milwaukee, '15., a corporation of Delaware No Drawing. Continuation of application Serial No. 636,493, January 28, 1957. This application August 30, 1957, Serial No. 681,189

1 Claim. (Cl. 260-294.7)

This invention relates to hydrazine. More particularly, this invention is concerned with novel hydrazines and the corresponding hydrazones and intermediates and processes used in producing such compounds.

This application is a continuation of my copending application Serial No. 636,493, filed January 28, 1957, now abandoned.

According to the present invention thereare provided novel hydrazines of the formula and processes and intermediates useful in preparing such compounds, wherein Am represents a nitrogen-containing heterocyclic stmcture, either mono or polycyclic, such as pyrrolidino, 3-hydroxypiperidino and 4-hydroxypiperidino and esters and ethers thereof, tetrahydroisoindolino, and I, 2, 3, 4-tetrahydroisoquinolino and R and R are hydrogen; alkyl groups, preferably lower alkyl groups of 1-8 carbons; or aralkyl groups, such as monocarbocyclic aryllower alkyl groups, and particularly phenyl-lower alkyl groups.

Production of primary hydrazines of the formula may be conveniently achieved by reacting a cyclicsecondary amine having the nitrogen in the ring with nitrous acid to form the corresponding nitrosoa'mine and reducing said nitrosoamine to the desired hydrazines. This reaction may be represented broadly as follows:

wherein Am has the significance previously assigned, and more specifically as follows, starting with a hydroxypiperidine or an ester or ether thereof:

H NHa wherein R represents hydrogen, a lower alkyl group, a monocyclic aryl group such as phenyl, a monocyclic aryllower alkyl group such as phenylmethyl and phenylethyl, a nuclear substituted monocyclic aryl-lower alkyl group such as p-hydroxyphenylmethyl, a disubstituted aminolower alkyl group such as dimethylaminoethyl, and N- lower alkyl piperidyl group such as N-ethyl piperidyl, a heterocyclic alkyl group such as furfuryl or thienyl, an acyl group derived from a lower carboxylic acid such as the acetyl and propionyl groups, a monocyclic aryl-acyl group in which the acyl group is derived from a lower carboxylic acid such as phenylacetyl, benzoyl, 7-theophylline acetyl, nicotinyl and picolinyl, with the OR group being located in the 3 or 4 position of the piperidine nucleus.

Production of such compounds may be conveniently achieved by reacting a cyclic secondary amine with nitrous acid at room temperature. The reaction may be conveniently effected in water and, in this regard, it is preferred to form the nitrous acid in situ by the use of an aqueous mixture of sodium nitrite and sulfuric acid. The reaction is completed in l to 2 hours. The desired nitrosoamine may be recovered by extracting the reaction mixture with an immiscible organic solvent, such as ether, and separated by evaporation of the solvent.

Usually, however, the nitrosoamine is not isolated but instead is reacted as present in the organic solvent with a reducing agent. Lithium aluminum hydride is the preferred reducing agent although catalytic processes may aiso he used. In addition to ether, dioxane, tetrahydrofuran, and the like may be used as reaction media in which to eiiect the reduction with lithium aluminum hydride. Elevated temperatures such as the reflux. temperature enhance the reaction. At reflux temperatures, from 1 to 8 hours is usually suificient to substantially complete the reaction. After the reaction is terminated, water may be added to the mixture to decompose excess lithium aluminum hydride. To recover the product, the organic phase is separated and the aqueous residue extracted with the same solvent. The organic phase and extracts then may be combined, dried and the product distilled.

Representative compounds produced .in this Way are N-amino-l, 2, 3, 4-tetrahydroisoquinoline, N-amino-pyrrolidine, N-amino-tetrahydroisoindoline, N-amino-3-hydroxypiperidine and N-amino-4-hydroxypiperidine and ethers and esters of the hydroxypiperidines as set forth previously.

N-(N lower alkyl)-amino heterocyclic amines and N-(N-aryl-lower alkyl)-amino heterocyclic amines are produced by reacting the primary hydrazines with a lower alkyl aldehyde or aryl-alkyl aldehyde and subsequently reducing the intermediate hydrazone to the desired N,N- substituted hydrazines. This process may be represented as follows:

wherein Am has the significance previously assigned and R is hydrogen, a lower alkyl group, an aryl group such as phenyl, or an aryl-lower alkyl group, particularly a monocarbocyclic aryl-lower alkyl group such as a phenyllower alkyl group.

Among the aldehydes which may be used in this process are formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, benzaldehyde, phenylacetaldehyde and the like.

The aldehyde and hydrazine react in the presence of water. Room temperature may be used although elevated temperatures such as the reflux temperature serve to increase the reaction rate. From 1 to 5 hours is usually suificient to complete the reaction. Recovery of the hydrazone is conveniently achieved by conventional procedures. Thus, an alkali metal hydroxide may be used to salt out the product which may then be extracted with an organic solvent such as ether. The product may be isolated by distillation under reduced pressure.

Representative of the hydrazones so produced are N- methylidenylamino-l, 2, 3, 4-tetrahydroisoquinoline, N- ethylidenylaminopyrrolidine, N-propylidenylamino-3-hydroxypiperidine, N hexylidenylamino 3 hydroxypiperidine, N-benzylidenylamino-4-hydroxypiperidine, N-phenylethylidenylamino-tetrahydroisoindoline and the like.

These hydrazones and others within this invention are conveniently reduced chemically or catalytically to the corresponding hydrazines. Lithium aluminum hydride is the preferred reducing agent. The reduction with this agent may be conveniently effected by intimately combining the reactants in an inert organic solvent such as anhydrous ether, dioxane and tetrahydrofuran. Elf).

(3 a a vated temperatures such as the reflux temperature enhance the reaction. At reflux temperature, from 1 to 8 hours is usually sufficient to substantially complete the reaction. After the reaction is terminated, water may be added to the mixture to decompose excess lithium aluminum hydride. To recover the product, the organic phase is separated and the aqueous residue extracted with the same solvent. The organic phase and extracts then may be combined, dried, and the product distilled.

The N-(N'-lower alkyl) -'lIXllIl0 heterccyclic amines and N-(N'-aryl-lower all yl)-amino heterocyclic amines may also be produced by two additional processes.

One of these processes comprises reacting the primary hydrazine with a lower alkyl ester of a lower carboxylic acid or aryl-alkyl carboxylic acid followed by reduction of the intermediate hydrazide. This process may be represented as follows:

AmNI-n+R O -0 R AmNH( JR AmNH o HzR wherein Am and R have the significance previously assigned, and R is a lower alkyl group.

Ethyl formate, methyl acetate, ethyl propionate, methyl butyrate, methyl 'benzoate and ethyl phenylacetate are representative esters which may be used in the process.

Reaction is conveniently achieved by refluxing the primary hydrazine and ester under suitable solvent conditions. Esters which are liquid may function both as reactant and solvent. The reaction is completed generally in several hours after which the excess solvent and reactant is removed by'distillation. The product may be crystallized from a suitable solvent.

Some hydrazides prepared in this way are N-(N- formyl) amino-l,2,3,4-tetrahydroisoquinoline, N-(N- acetyl) amino-pyrrolidine, l methyl-4-(N-benzoyl)- amino-3 -hydroxypiperidine, N-(N'-phenylacetyl) -aminotetrahydroisoindoline, N (N-acetyl)-arnino-3-hydroxypiperidine and N-(N-formyl)-amino-4-hydroxy-piperidine.

These and other hydrazides may be conveniently reduced to the corresponding hydrazines with a suitable reducing agent of which lithium aluminum hydride is preferred.

The primary hydrazines may also be substituted by reacting them with a suitable acid halide followed by reduction of the intermediate hydrazide. This process may be represented as follows:

as triethylamine or tri-n-propylamine. After the reaction the hydrazide may be recovered by conventional procedures.

The secondary hydrazines of the formula wherein R has the significance previously assigned, may be further alkylated with an alkyl or aralkyl halide or a lower alkyl ester of a lower carboxylic acid or aryl-lower carboxylic acid. These reactions may be represented as follows:

l wherein Am, R R and X have the significance previously assigned, and R is hydrogen, a lower alkyl group, or an aryl-lower alkyl group, particularly a monocarbocyclic aryl-lower alkyl group such as a phenyl-lower alkyl group.

Thus, N (N methyl)-amino-l,2,3,4-tetrahydroisoquinoline may be reacted with ethylformate to form N- (N methyl N formyl)-amino-1,2,3,4-tetrahydroisoquinoline which hydrazide upon reduction yields N- (N,N-dirnethyl) -amino-1,2,3,4-tetrahydroisoquinoline.

Similarly, N (N ethyl)-amino-3-hydroxypiperidine may be reacted with acetyl chloride to form N-(N'-ethyl- N -acetyl) -amino-3-hydroxypiperidine which is reduced to N-(N'-N-diethyl)amino-3 -hydroxypiperidine.

The hydrazones and hydrazines form acid addition salts and quaternary ammonium salts.

Acid addition salts are produced by contacting the hydrazines with a suitable acid such as a mineral acid like sulfuric acid or hydrochloric acid or organic acids such as formic acid, citric acid, maleic acid and complex acids such as penicillin. Generally, one mole of the hydrazine compound reacts with one mole equivalent of acid.

Quaternary ammonium salts of the hydrazines are prepared by contacting the bases with alkylating agents, preferably in the presence of a suitable organic solvent. Alkylating agents such as lower alkyl halides, including methyl chloride, ethyl bromide, methyl bromide, alkylating agents like methyl and ethyl sulphate, as well as aryl substituted alkyl-ating agents like o-chlorobenzyl bromide,

phenylethyl chloride, and phenylpropyl bromide are representative compounds which form quaternary ammonium salts with the hydrazines.

The compounds, as non-toxic acid addition salts, have long-acting diuretic activity. In addition, these compounds are useful intermediates in the production of other compounds having diuretic activity as disclosed in my copending application Serial No. 636,491, filed January 28, 1957.

The following examples are presented to show methods of producing certain of the novel compounds included within this invention. It is to be understood, however, that these examples are included only for purposes of illustration, and that the invention is not to be restricted tothe embodiments specifically disclosed therein.

EXAMPLE 1 N-nitroso 3-hydroxypiperidine To 50.5 g. (0.5 mole) of 3-hydroxypiperidine and 50.5 g. of water was added 128 g. (0.39 mole) of sulfuric acid (30%) with stirring and cooling. While holding the temperature at 10-15 C., a solution of g. (1.23 mole) of sodium nitrite and 150 cc. of water was added in one hour. The solution was warmed to 25 C. and stirred for an additional hour. The compound was extracted from the aqueous. layer with three cc. portions of chloroform. The combined extracts were washed with 30 cc. (40%) of potassium hydroxide solution, and dried briefly over anhydrous potassium carbonate. The chloroform was distilled 0d and the residue could not be distilled under vacuum.

Yield 40.85 g. or 62.8%.

The residue was used as such in Example 2.

EXAMPLE 2 N-amino-3-hydroxypiperidine To 17.5 g. (0.45 mole) of lithium aluminum hydride in 500 cc. of freshly distilled tetrahydrofuran was added a solution of 40.85 g. (0.314 mole) of N-nitroso 3-hydroxypiperidine diluted with 300 cc. of tetrahydrofuran in a period of ninety minutes. The mixture was refluxed for one hour, and then the complex was decomposed with 100 cc. (40%) of potassium hydroxide solution. The tetrahydrofuran solution was decanted off the inorganic salts, which were washed with additional tetrahydrofuran.

U The solvent was distilled oif through a 10" Vigreux column and the product was vacuum distilled. B.P. 84-86 C. (0.45 mm.).

Yield 25.9 g. or 71%. M.P. 85-86 C.

added to 210 g. of ethyl formate and the mixture refluxed for 4 hours on the steam bath. The excess ethyl iormate was removed by distillation, and 27 g. of solid remained which was recrystallized from 55 cc. of hot ethanol.

Analysis.-Calcd. for C H N O: N, 12.05. Found: 5 Yield 13.8 g. M.P. 129 C. N, 12.04. Analysis.--Calcd. for C H N o: N, 7.95. Found:

EXAMPLE 3 N, 7.87. N-amino-l,2,3,4-tetrahydroisquinoline EXAMPLE 6 I I To 26.6 g. of 1,2,3,4-tetrahydroisoquinoline in 120 cc. 10 N (N 'methy I) drolsoqumolme of water are added with stirring and cooling 51 g. of 30% aqueous H 80 The mixture is cooled to 5-10 C. and 34.2 g. of sodium nitrite dissolved in 60 cc. of water N-NH-OH; added, keeping the temperature below C. After the addition is completed, stirring is continued at room 5 To 34 09 mole) of LiAlH1 in 150 cc. of temperatur? for two hours- The aqueous Suspenslo? 1S hydrofuran was added with stirring a solution of 13.6 g. extracted wlth ether and the ether extracts washed with (L077 mole) of N (N' formyl) amino tetrahydmiso concentrated PQtaSSHKm i Sohmon' The ether quinoline in 160 cc. of tetrahydrofuran. The mixture extracts are dned WP potassuim carboltate and then was refluxed for 4 hours, the complex decomposed with added to 8.8 g. of l1th1um aluminum hydride suspended 40% aqueous KOH and the product isulated by disti11a in 100 cc. of anhydrous ether. After completion of the lion BR C (0.85 mm addition, the mixture is stirred for two hours With Yield 103 g N 2011573 refluxing and the complex decomposed with 40% aqueous AnalySl-S C'a1cd H N 8 64 Found. potassium hydroxide. The ether layer is decanted and N 14 dried with K 00 The product is collected by distillamaleate Salt was Prepared in ethanol MP tiOn; B-P. 85 C. 111111.). 156 157o C. I NAgngyszs-Calcd. for C H N N, 9.45. Found: Analysisl calcd. for C1DH14N2 C4H4O4: N, 504; EXAMPLE 4 maleic acid content: 41.71. Found: N, 5.00; maleic acid content: 43.12. By following the procedures of Examples 1 through 3, The mono-hydrochloride salt was prepared in ethanol, and using as starting materials the appropriate cyclic M.P. 186-l87 C. secondary amines, the following hydrazines and salts Analysis.-Calcd. for C H ClN Cl, 17.85; N, 6.90. thereof were produced: Found: C1, 1790; N, 7.05.

Percent Percent Percent Nitrogen M .P., Chloride Malelc Acid Hydrazine O./m1n. N020 Salts O.

Caled. Found Calcd. Found Oalcd. Found 1 NNH, 53/40 1. 4090 16.28 15. 34

3 86/0. 55 1. 5793 0.45 0.35 gg g fig: }43 02 40.07

N-NH,

4 0H 85/05 12.05 12.04 Maleate 84 :43.03 0.04 50.00 50. 00

N 5H. 0H

5 sea/0.15 12.05 11.50

i NHQ Nitrogen assay: Oalcd. 7.59. Found: N, 7.64. b Nitrogen assay.

EXAMPLE 5 EXAMPLE 7 N -formylamin0-J ,2,3,4-tetrahydroisoquinoline N N '-m ethyl-N -f0rmyl -amino-1 ,2,3,4-tetrahydroisoquinoline o N-NH-("J-H N-N 21 g. of N-amino-1,2,3,4-tetrahydroisoquinoline was C 7 A mixture containing 16.2 g. (0.10 mole) of the compoundof Example-6 and- 1 11 g. (1.5 mole) of ethyl forma-te Was refluxed for 7 "hours.

N- N,N-dimethyl) hmin0-1,2,3,4-tetrahydr0is0- quinoline The formyl derivative of Example 7 was reduced in the manner described in Example 6. Yield 13.7 g. (77%);

B.P. 85 C. (0.5 mm.) N 1.5451.-

Analysis.Calcd. for C H N N, 7.95. Found:

EXAMPLE 9 N (N ,N '-dimie;thyl -amin0-1 ,2 ,3,4-tetrahydroisoquinoline hydrochloride "Found: Cl, 16.12; N, 6.69.

EXAMPLE 10 N -(N '-methyl -amin0-1 ,2,3,4-terahydr0is quinoline hydrochloride The base of Example 6 was converted to the hydrochloride in ethyl alcohol, M.P. 186-187" C.

Analysis.--Calcd. for C H ClN Cl, 17.85; N, 6.90. Found: C1, 17.90; N, 6.85. 1 i

Various changes and modifications .of the invention can be made and, to the extent that such variations incorporate the spirit of'this invention, they are intended to be included within the scope of the appended claim.

What is claimed is:

N-amino-3-hydroxypiperidine.

References Cited in the file of this patent UNITED STATES PATENTS 2,636,006 Ross Apr. 21, 1953 OTHER REFERENCES Carrara et al.: Gazz. Chirn. et 211., vol. 83, pp. 459-75 (1953).

Beilstein: Handbuch der org. Chem, 4th ed., 1935, vol. 20, pp. 271 andr279.

Chemical Abstracts, Decennial Index, vols. 1-10, 1907- 1916, p. 4011.

Groschuff: Annalen der Chemie, vol. 417, pp. 181-189 Zimmer et al.: Jour. Amer. Chem. Soc., vol. 77, pp. 790-3 (1955).

Beilstein: Handbuch der organischen Chernie, vol. 20, pp. 6 and 261 (1935).

Cook et al.: Jour. Phys. Chemistry, vol. 36. PP. 2383-9 (1932). 

